New NASA Software Simulates Science Missions for Observing Terrestrial Freshwater

New NASA Software Simulates Science Missions for Observing Terrestrial Freshwater

4 min read

New NASA Software Simulates Science Missions for Observing Terrestrial Freshwater

Global map; different colored areas on each continent show the varying levels of freshwater
A map describing freshwater accumulation (blue) and loss (red), using data from NASA’s Gravity Recovery and Climate Experiment (GRACE) satellites. A new Observational System Simulation Experiment (OSSE) will help researchers design science missions dedicated to monitoring terrestrial freshwater storage. Image Credit: NASA
Image Credit: NASA

From radar instruments smaller than a shoebox to radiometers the size of a milk carton, there are more tools available to scientists today for observing complex Earth systems than ever before. But this abundance of available sensors creates its own unique challenge: how can researchers organize these diverse instruments in the most efficient way for field campaigns and science missions?

To help researchers maximize the value of science missions, Bart Forman, an Associate Professor in Civil and Environmental Engineering at the University of Maryland, and a team of researchers from the Stevens Institute of Technology and NASA’s Goddard Space Flight Center, prototyped an Observational System Simulation Experiment (OSSE) for designing science missions dedicated to monitoring terrestrial freshwater storage.

“You have different sensor types. You have radars, you have radiometers, you have lidars – each is measuring different components of the electromagnetic spectrum,” said Bart Forman, an Associate Professor in Civil and Environmental Engineering at the University of Maryland. “Different observations have different strengths.”

Terrestrial freshwater storage describes the integrated sum of freshwater spread across Earth’s snow, soil moisture, vegetation canopy, surface water impoundments, and groundwater. It’s a dynamic system, one that defies traditional, static systems of scientific observation.

Forman’s project builds on prior technology advancements he achieved during an earlier Earth Science Technology Office (ESTO) project, in which he developed an observation system simulation experiment for mapping terrestrial snow. 

It also relies heavily on innovations pioneered by NASA’s Land Information System (LIS) and NASA’s Trade-space Analysis Tool for Designing Constellations (TAT-C), two modeling tools that began as ESTO investments and quickly became staples within the Earth science community.

Forman’s tool incorporates these modeling programs into a new system that provides researchers with a customizable platform for planning dynamic observation missions that include a diverse collection of spaceborne data sets.

In addition, Forman’s tool also includes a “dollars-to-science” cost estimate tool that allows researchers to assess the financial risks associated with a proposed mission.

Together, all of these features provide scientists with the ability to link observations, data assimilation, uncertainty estimation, and physical models within a single, integrated framework.

“We were taking a land surface model and trying to merge it with different space-based measurements of snow, soil moisture, and groundwater to see if there was an optimal combination to give us the most bang for our scientific buck,” explained Forman.

While Forman’s tool isn’t the first information system dedicated to science mission design, it does include a number of novel features. In particular, its ability to integrate observations from spaceborne passive optical radiometers, passive microwave radiometers, and radar sources marks a significant technology advancement.

Forman explained that while these indirect observations of freshwater include valuable information for quantifying freshwater, they also each contain their own unique error characteristics that must be carefully integrated with a land surface model in order to provide estimates of geophysical variables that scientists care most about.

Forman’s software also combines LIS and TAT-C within a single software framework, extending the capabilities of both systems to create superior descriptions of global terrestrial hydrology.

Indeed, Forman stressed the importance of having a large, diverse team that features experts from across the Earth science and modeling communities.

“It’s nice to be part of a big team because these are big problems, and I don’t know the answers myself. I need to find a lot of people that know a lot more than I do and get them to sort of jump in and roll their sleeves up and help us. And they did,” said Forman.

Having created an observation system simulation experiment capable of incorporating dynamic, space-based observations into mission planning models, Forman and his team hope that future researchers will build on their work to create an even better mission modeling program.

For example, while Forman and his team focused on generating mission plans for existing sensors, an expanded version of their software could help researchers determine how they might use future sensors to gather new data.

“With the kinds of things that TAT-C can do, we can create hypothetical sensors. What if we double the swath width? If it could see twice as much space, does that give us more information? Simultaneously, we can ask questions about the impact of different error characteristics for each of these hypothetical sensors and explore the corresponding tradeoff.” said Forman.

PROJECT LEAD

Barton Forman, University of Maryland, Baltimore County

SPONSORING ORGANIZATION

NASA’s Advanced Information Systems Technology (AIST) program, a part of NASA’s Earth Science Technology Office (ESTO), funded this project

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NASA Remembers Former NASA Johnson Director George W. S. Abbey

NASA Remembers Former NASA Johnson Director George W. S. Abbey

March 25, 2024

Johnson Space Center Director George Abbey
Former NASA Johnson Space Center Director George W. S. Abbey

RELEASE J24-008

NASA Remembers Former NASA Johnson Director George W. S. Abbey

George W. S. Abbey, former director of NASA’s Johnson Space Center, died Sunday, March 24, in Houston after an illness. The Seattle native was 91. 

“A true visionary, Mr. Abbey demonstrated transformational leadership as Johnson’s seventh center director. During his tenure, the space shuttle flew more than 25 successful missions; the joint U.S. and Russian Shuttle-Mir Program was completed, providing important information for long-duration spaceflight,” said Vanessa Wyche, director of NASA Johnson. “He was instrumental in the Johnson team’s involvement in developing and launching the first elements of the International Space Station, which marked the beginning of a new era in space exploration. On behalf of NASA’s Johnson Space Center, we send our condolences to Mr. Abbey’s loved ones during this difficult time.”

Abbey had a long and storied career in human spaceflight that began with NASA in 1964 and continued beyond his retirement from the agency. As the director of flight operations, he oversaw selection of NASA’s first space shuttle astronauts, mission operations, and the new shuttle program’s approach and landing tests.

From 1987 to 1993, Abbey supported NASA Headquarters in Washington, serving in key roles in human spaceflight, and on the National Space Council. He returned to Johnson in 1994, first as deputy director, then director, leading the development and launch of the space station. Abbey retired from the agency in 2003.

In December 2021, NASA named the Saturn V rocket display park outside Johnson’s main gate for Abbey. Abbey instituted the Longhorn Project, a vital STEM program that provides students with hands-on agricultural experiences and academic scholarships. He leaves behind a legacy of excellence and lasting impact as he will continue to inspire over 1.2 million visitors who visit the George W.S. Abbey Rocket Park annually.

“Abbey’s dedication to human spaceflight remained steadfast. As the NASA family mourns his passing, we are grateful for his leadership and the legacy he leaves behind,” Wyche said.

Abbey is survived by his five children, his eight grandchildren, three great-grandchildren, nieces, and nephews.

Learn more about Abbey’s career in support of NASA at:

https://www.nasa.gov/people/george-w-s-abbey/

-end-

Kelly Humphries / Nilufar Ramji

Kelly.o.humphries@nasa.gov / niliufar.ramji@nasa.gov

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Wendy K. Avedisian

NASA to Launch Sounding Rockets into Moon’s Shadow During Solar Eclipse

NASA to Launch Sounding Rockets into Moon’s Shadow During Solar Eclipse

5 min read

NASA to Launch Sounding Rockets into Moon’s Shadow During Solar Eclipse

NASA will launch three sounding rockets during the total solar eclipse on April 8, 2024, to study how Earth’s upper atmosphere is affected when sunlight momentarily dims over a portion of the planet.

The Atmospheric Perturbations around Eclipse Path (APEP) sounding rockets will launch from NASA’s Wallops Flight Facility in Virginia to study the disturbances in the ionosphere created when the Moon eclipses the Sun. The sounding rockets had been previously launched and successfully recovered from White Sands Test Facility in New Mexico, during the October 2023 annular solar eclipse. They have been refurbished with new instrumentation and will be relaunched in April 2024. The mission is led by Aroh Barjatya, a professor of engineering physics at Embry-Riddle Aeronautical University in Florida, where he directs the Space and Atmospheric Instrumentation Lab.

A group of people wearing blue jackets pose for the picture. They stand inside a tall, industrial room. Three silver rockets are behind them.
This photo shows the three APEP sounding rockets and the support team after successful assembly. The team lead, Aroh Barjatya, is at the top center, standing next to the guardrails on the second floor.
NASA/Berit Bland

The sounding rockets will launch at three different times: 45 minutes before, during, and 45 minutes after the peak local eclipse. These intervals are important to collect data on how the Sun’s sudden disappearance affects the ionosphere, creating disturbances that have the potential to interfere with our communications.

This conceptual animation is an example of what observers might expect to see during a total solar eclipse, like the one happening over the United States on April 8, 2024.
NASA’s Scientific Visualization Studio.

The ionosphere is a region of Earth’s atmosphere that is between 55 to 310 miles (90 to 500 kilometers) above the ground. “It’s an electrified region that reflects and refracts radio signals, and also impacts satellite communications as the signals pass through,” said Barjatya. “Understanding the ionosphere and developing models to help us predict disturbances is crucial to making sure our increasingly communication-dependent world operates smoothly.”

The ionosphere forms the boundary between Earth’s lower atmosphere – where we live and breathe – and the vacuum of space. It is made up of a sea of particles that become ionized, or electrically charged, from the Sun’s energy, or solar radiation. When night falls, the ionosphere thins out as previously ionized particles relax and recombine back into neutral particles. However, Earth’s terrestrial weather and space weather can impact these particles, making it a dynamic region and difficult to know what the ionosphere will be like at a given time. 

A cartoon Earth becomes shadowed as it turns from day to night, to day again. Red swirls sweep across the planet when it's daytime. Satellites orbit around the planet.
An animation depicts changes in the ionosphere over a 24-hour period. The red and yellow swaths represent high-density ionized particles during the day. The purple dots represent neutral, relaxed particles at night.
NASA/Krystofer Kim

It’s often difficult to study short-term changes in the ionosphere during an eclipse with satellites because they may not be at the right place or time to cross the eclipse path. Since the exact date and times of the total solar eclipse are known, NASA can launch targeted sounding rockets to study the effects of the eclipse at the right time and at all altitudes of the ionosphere.

As the eclipse shadow races through the atmosphere, it creates a rapid, localized sunset that triggers large-scale atmospheric waves and small-scale disturbances, or perturbations. These perturbations affect different radio communication frequencies. Gathering the data on these perturbations will help scientists validate and improve current models that help predict potential disturbances to our communications, especially high frequency communication. 

A map of the U.S. on a graph. The map is covered with light green, teal, and yellow dots. As the path of the Moon's shadow sweeps from the northwest US to the southeast US, the dots changed to a dark blue color.
The animation depicts the waves created by ionized particles during the 2017 total solar eclipse.
MIT Haystack Observatory/Shun-rong Zhang. Zhang, S.-R., Erickson, P. J., Goncharenko, L. P., Coster, A. J., Rideout, W. & Vierinen, J. (2017). Ionospheric Bow Waves and Perturbations Induced by the 21 August 2017 Solar Eclipse. Geophysical Research Letters, 44(24), 12,067-12,073. https://doi.org/10.1002/2017GL076054.

The APEP rockets are expected to reach a maximum altitude of 260 miles (420 kilometers). Each rocket will measure charged and neutral particle density and surrounding electric and magnetic fields. “Each rocket will eject four secondary instruments the size of a two-liter soda bottle that also measure the same data points, so it’s similar to results from fifteen rockets, while only launching three,” explained Barjatya. Three secondary instruments on each rocket were built by Embry-Riddle, and the fourth one was built at Dartmouth College in New Hampshire.

In addition to the rockets, several teams across the U.S. will also be taking measurements of the ionosphere by various means. A team of students from Embry-Riddle will deploy a series of high-altitude balloons. Co-investigators from the Massachusetts Institute of Technology’s Haystack Observatory in Massachusetts, and the Air Force Research Laboratory in New Mexico, will operate a variety of ground-based radars taking measurements. Using this data, a team of scientists from Embry-Riddle and Johns Hopkins University Applied Physics Laboratory are refining existing models. Together, these various investigations will help provide the puzzle pieces needed to see the bigger picture of ionospheric dynamics.

A sounding rocket is able to carry science instruments between 30 and 300 miles above Earth’s surface. These altitudes are typically too high for science balloons and too low for satellites to access safely, making sounding rockets the only platforms that can carry out direct measurements in these regions.
NASA’s Goddard Space Flight Center

When the APEP sounding rockets launched during the 2023 annular solar eclipse, scientists saw a sharp reduction in the density of charged particles as the annular eclipse shadow passed over the atmosphere. “We saw the perturbations capable of affecting radio communications in the second and third rockets, but not during the first rocket that was before peak local eclipse” said Barjatya. “We are super excited to relaunch them during the total eclipse, to see if the perturbations start at the same altitude and if their magnitude and scale remain the same.”

The next total solar eclipse over the contiguous U.S. is not until 2044, so these experiments are a rare opportunity for scientists to collect crucial data.

The APEP launches will be live streamed via NASA’s Wallops’ official YouTube page and featured in NASA’s official broadcast of the total solar eclipse. The public can also watch the launches in person from 1-4 p.m. at the NASA Wallops Flight Facility Visitor Center.

By Desiree Apodaca
NASA’s Goddard Space Flight Center, Greenbelt, Md.

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NASA’s OSIRIS-REx Mission Awarded Robert Goddard Memorial Trophy

NASA’s OSIRIS-REx Mission Awarded Robert Goddard Memorial Trophy

3 min read

Preparations for Next Moonwalk Simulations Underway (and Underwater)

NASA’s OSIRIS-REx team was selected as the winner of the National Space Club and Foundation’s 2024 Dr. Robert H. Goddard Memorial Trophy for their tremendous work on the first U.S. mission to bring an asteroid sample to Earth. The winning team  received the award at the 67th Annual Robert H. Goddard Memorial Dinner at the Washington Hilton Hotel on March 22, 2024.

The sample return capsule from NASA’s OSIRIS-REx mission is seen shortly after touching down in the desert, Sunday, Sept. 24, 2023, at the Department of Defense’s Utah Test and Training Range. The sample was collected from the asteroid Bennu in October 2020 by NASA’s OSIRIS-REx spacecraft.
NASA/Keegan Barber

The OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security – Regolith Explorer) team includes NASA’s Goddard Space Flight Center in Greenbelt, Maryland; Lockheed Martin in Littleton, Colorado; University of Arizona, Tucson and KinetX in Tempe, Arizona.

The trophy is National Space Club’s highest honor and presented annually to the individual or group who has made a substantial contribution to U.S. leadership in astronautics or rocketry.

“The OSIRIS-REx team’s successful delivery of the asteroid Bennu sample to Earth will enable important scientific discoveries for generations to come,” said Lori Glaze, director of the Planetary Science Division at NASA Headquarters in Washington. “I’m so pleased to see the mission team recognized with the Robert H. Goddard Memorial Trophy for their accomplishments.”

Making U.S. History

Following its launch in 2016, the OSIRIS-REx mission made U.S. space history when it became the first U.S. spacecraft to touch an asteroid and capture a sample on Oct. 20, 2020, and again when it successfully returned with the sample to Earth on Sept. 24, 2023.

The sample, which is the largest asteroid sample ever delivered to Earth, is from the ancient asteroid Bennu and will give researchers worldwide a glimpse into the earliest days of our solar system, offering insights into planet formation and the origin of organics that led to life on Earth. Data collected by the spacecraft combined with future analysis of the Bennu sample will also aid our understanding of asteroids that can impact Earth.

The OSIRIS-REx mission conducted unprecedented centimeter-scale mapping of Bennu, surpassing precision levels achieved for any other planetary body and setting three Guinness World Records for: smallest object orbited by a spacecraft, closest orbit of an asteroid and highest resolution satellite map of any planetary body.

“The OSIRIS-REx mission rewrote U.S. space exploration history,” said Joe Vealencis, president, NSCF. “The data the spacecraft collected, plus all that we have yet to uncover from the sample it brought back, means scientists and engineers will be reaping the benefits of this mission for years to come.”

The Mission Continues

Following its successful sample return, the OSIRIS-REx spacecraft was renamed OSIRIS-APEX and will now enter an extended mission to visit and study near-Earth asteroid Apophis in 2029.

OSIRIS-REx’s success was made possible by the unique contributions of over 1,000 individuals from government and mission partners like the science lead at the University of Arizona, the project team at NASA’s Goddard Space Flight Center, the curation team at NASA’s Johnson Space Center, spacecraft design, operations, and recovery by Lockheed Martin, guidance and navigation at KinetX, and the launch provider at United Launch Alliance.

OSIRIS-REx is the third mission in NASA’s New Frontiers Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the Science Mission Directorate at NASA Headquarters in Washington.

Find more information about NASA’s OSIRIS-REx mission at:

https://science.nasa.gov/mission/osiris-rex

Rob Gutro / Rani Gran
NASA’s Goddard Space Flight Center, Greenbelt, Md.

Karen Fox / Charles Blue
Headquarters, Washington
202-358-1257 / 202-802-5345

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Jamie Adkins

Antarctic Sea Ice Near Historic Lows; Arctic Ice Continues Decline

Antarctic Sea Ice Near Historic Lows; Arctic Ice Continues Decline

5 Min Read

Antarctic Sea Ice Near Historic Lows; Arctic Ice Continues Decline

On Feb. 20, 2024, Antarctic sea ice officially reached its minimum extent for the year. This cycle of growth and melting occurs every year, with the ice reaching its smallest size during the Southern Hemisphere’s summer.

Credits:
NASA’s Scientific Visualization Studio/Trent L. Schindler

Sea ice at both the top and bottom of the planet continued its decline in 2024. In the waters around Antarctica, ice coverage shrank to near-historic lows for the third year in a row. The recurring loss hints at a long-term shift in conditions in the Southern Ocean, likely resulting from global climate change, according to scientists at NASA and the National Snow and Ice Data Center. Meanwhile, the 46-year trend of shrinking and thinning ice in the Arctic Ocean shows no sign of reversing.

“Sea ice acts like a buffer between the ocean and the atmosphere,” said ice scientist Linette Boisvert of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Sea ice prevents much of the exchange of heat and moisture from the relatively warm ocean to the atmosphere above it.”

Less ice coverage allows the ocean to warm the atmosphere over the poles, leading to more ice melting in a vicious cycle of rising temperatures.

Historically, the area of sea ice surrounding the Antarctic continent has fluctuated dramatically from year to year while averages over decades have been relatively stable. In recent years, though, sea ice cover around Antarctica has plummeted.

On Feb. 20, 2024, Antarctic sea ice officially reached its minimum extent for the year. This cycle of growth and melting occurs every year, with the ice reaching its smallest size during the Southern Hemisphere’s summer. According to the National Snow and Ice Data Center, this marks the second-lowest sea ice extent recorded by satellites, reflecting a trend of declining coverage over time.
Credit: NASA’s Goddard Space Flight Center/Scientific Visualization Studio
Download this video in HD formats from https://svs.gsfc.nasa.gov/14538.

“In 2016, we saw what some people are calling a regime shift,” said sea ice scientist Walt Meier of the National Snow and Ice Data Center at the University of Colorado, Boulder. “The Antarctic sea ice coverage dropped and has largely remained lower than normal. Over the past seven years, we’ve had three record lows.”

This year, Antarctic sea ice reached its lowest annual extent on Feb. 20 with a total of 768,000 square miles (1.99 million square kilometers). That’s 30% below the 1981 to 2010 end-of-summer average. The difference in ice cover spans an area about the size of Texas. Sea ice extent is defined as the total area of the ocean in which the ice cover fraction is at least 15%.

This year’s minimum is tied with February 2022 for the second lowest ice coverage around the Antarctic and close to the 2023 all-time low of 691,000 square miles (1.79 million square kilometers). With the latest ice retreat, this year marks the lowest three-year average for ice coverage observed around the Antarctic continent across more than four decades.

The changes were observed in data collected with microwave sensors aboard the Nimbus-7 satellite, jointly operated by NASA and the National Oceanic and Atmospheric Administration (NOAA), along with satellites in the Defense Meteorological Satellite Program.

Meanwhile, at the other end of the planet, the maximum winter ice coverage in the Arctic Ocean is consistent with an ongoing 46-year decline. Satellite images reveal that the total area of the Arctic Ocean covered in sea ice reached 6 million square miles (15.65 million square kilometers) on March 14. That’s 247,000 square miles (640,000 square kilometers) less ice than the average between 1981 and 2010. Overall, the maximum winter ice coverage in the Arctic has shrunk by an area equivalent to the size of Alaska since 1979.

This year’s Arctic ice maximum is the 14th lowest on record. Complex weather patterns make it difficult to predict what will happen in any given year.

An illustrated graph depicting the annual fluctuation of ice in the Arctic. The x-axis shows January through December while the y-axis starts at 2 and goes up to 16 by 2's, depicting the millions of square kilometers. Several lines go across the graph in blue, red, orange, and pink colors. The lines are dotted and dashedd or show a larger area. The lines move closely together in a wave-like motion starting from the top left of the graph and moving to the right. The lines peak in March and reach a minimum in September.
The Arctic Ocean sea ice reached its annual maximum on March 14, continuing the long-term decline in ice at the poles.
Chart by Lauren Dauphin/NASA Earth Observatory, using data from the National Snow and Ice Data Center.

Shrinking ice makes Earth more susceptible to solar heating. “The sea ice and the snow on top of it are very reflective,” Boisvert said. “In the summer, if we have more sea ice, it reflects the Sun’s radiation and helps keep the planet cooler.”

On the other hand, the exposed ocean is darker and readily absorbs solar radiation, capturing and retaining that energy and ultimately contributing to warming in the planet’s oceans and atmosphere. 

Sea ice around the poles is more susceptible to the weather than it was a dozen years ago. Ice thickness measurements collected with laser altimeters aboard NASA’s ICESat-2 satellite show that less ice has managed to stick around through the warmer months. This means new ice must form from scratch each year, rather than building on old ice to make thicker layers. Thinner ice, in turn, is more prone to melting than multi-year accumulations.

“The thought is that in a couple of decades, we’re going to have these essentially ice-free summers,” Boisvert said, with ice coverage reduced below 400,000 square miles (1 million square kilometers) and most of the Arctic Ocean exposed to the Sun’s warming glare.

It’s too soon to know whether recent sea ice lows at the South Pole point to a long-term change rather than a statistical fluctuation, but Meier believes long term declines are inevitable.

“It’s only a matter of time,” he said. “After six, seven, eight years, it’s starting to look like maybe it’s happening. It’s just a question of whether there’s enough data to say for sure.”

By James Riordon
NASA’s Earth Science News Team

Media contact: Elizabeth Vlock
NASA Headquarters

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Mar 25, 2024

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Jennifer M. Fadoul